1. Field of the Invention
The present invention relates to a class of work holding device, or grasshopper clamps in general, and more particularly to welding finger having a slidable L-shape front clamping leg with copper tip, a pair of slidable L-shape rear clamping legs with copper tips, a relatively heavy body, a spring clip mounted on the front clamping leg and a braided ground wire connected to the body. The present invention is a convenient and easy to use work holding device specially designed for welding industry. To clamp a workpiece for welding, just lay the present invention on a welding table with its rear clamping legs touching the table surface and place the workpiece between the front clamping leg and the table surface. The weight of the body will hold the workpiece against the table surface steadily and ready for welding. Both the front and the rear clamping legs are made to be slidable on the body so that the lengths between the copper tips and the body are adjustable. Hence the clamping force applied to the workpiece against the table surface is also adjustable. If the shape of the workpiece is so odd that it cannot be held firmly by the front clamping leg against the table surface, then the spring clip will be used instead. To ground the workpiece for welding, a ground clamp is used to clamp the free end of the braided ground wire instead of the body of the present invention. Since the braided ground wire is flexible, the use of a ground clamp will not disturb the clamping setup of the workpiece.
2. Description of the Related Art
Grasshopper clamps have been used in the welding industry for a while. It is a very simple device and very convenient to use. It comprises a relatively heavy body and three L-shape legs mounted to the body. Just put the grasshopper clamp on a welding table and put the workpiece between one of the legs and the surface of the welding table. The weight of the body will provide the clamping force required to hold the workpiece steadily in place for welding purpose.
Conventionally, the three legs are fixed to the body so that the length between the clamping tip of a leg and the center of gravity of the body is not adjustable. This will limit the application of the grasshopper to limited sizes of workpieces. It is the intention of the present invention to solve this problem by making both the front and rear clamping legs slidable over the body. The clamping legs of a conventional grasshopper is usually made of iron. This may cause sparkling between the workpiece and the clamping tips during the welding process. The present invention eliminates this problem by adding copper tips to the clamping legs. To enhance the flexibility of the present invention, a spring clip is attached to the front clamping leg. This spring clip can be used to hold on a workpiece with special shape or hold on a second workpiece while the front clamping leg is holding a first workpiece. For better conductivity and convenience, a braided ground wire is connected to the body of the present invention. During the welding process, a ground clamp will clamp the free end of the braided ground wire instead of the body of the present invention. Thus the clamping action of the ground clamp will not affect the work holding setup of the present invention.